Presser foot for sewing machines



Feb. 3, 1953 R. E. JOHNSON ETAL 2,627,240

PRESSER FOOT FOR SEWING MACHINES Filed Jan. 24, 1951 2 SHEETS-SHEET l7n/venan. RaZp/IEJohnson and Charles LKessler Wiring@ .@(y.

Feb 3', 1953 R. E JoHNsoN ETAL 2,627,240

PRESSER FOOT FOR SEWING MACHINES Filed Jan. 24, 1951 2 SHEETS-SHEET 2 vmill/W my /J0 32 Y f- V O 54? l ///\y Y l?? Raz 17E. 2,232@- wiinm @yClarles ljLKess WXQWJ/ y Patented Feb. 3, 1953 PRESSER FOOT FOR SEWING`MACHINES Ralph E. Johnson, Mountainside, and Charles A, Kessler,Plainfield, N. J., assignors to The Sing-er Manufacturing Company, N.J., a corporationl of New Jersey Elizabeth,

Application January 24, 1951, Serial No, 207,532`

lllaims. l

rIhis invention relates to sewing machine presser-feet and moreparticularly to. a presserfoot which is adapted to be employed in thestitching of elastic material.

The present presser-foot` was developed in an effort to overcome thepuckering eiect which is produced in elastic cloth, such as nylonf whenit is stitched` with elastic thread. This puckering effect is producedin the work material by the thread which, due to its elastic nature, isstretched during the stitch-,forming operation with the result that thetensioned stitches tend to gather the work material upon the completionof the sewing operation in a manner as illustrated in Fig. 2 of theaccompanying drawings.

The foregoing object and others ancillary thereto have been attained bythe provision of a novel presser-foot which functions in cooperationwith the conventional type four-motion feeddog, to stretch the elasticwork material during its progress past the stitching area of a sewing machine so that when the stitches are formed in the work material thelatter will be stretched to the end that the resulting stitched materialwill have no tendency to pucker.

With the above and other objects in View, as will hereinafter appear,the invention comprises the devices, combinations and arrangements oiparts hereinafter set forth and illustrated in the accompanying drawingsof a preferred embodiment of the invention, from which the severalfeatures of the invention and the advantages attained thereby will bereadily understood by those skilled in the art.

In the drawings,

Fig. 1 represents an end elevation, partly in section, of astitch-forming and feeding mechanism of a sewing machine showing theimproved presser-foot.

Fig. 2 represents an enlarged longitudinalsectional View through a pairof stitched plies of work-material and illustrating a puckered effectwhich is produced by a conventional sew-ing machine when elasticneedle-thread s used in the stitching of elastic WOrk material,

Fig. 3 represents an enlarged longitudinal sectional view through a pairof stitched plies of work material as produced on a sewing machineemploying the present invention and utilizing elastic Work material andelastic needle thread.

Fig. 4 represents an enlarged right side View, partly in section, ofthepresser-foot and feed-dog illustrated in Fig. 1.

Fig. 5 represents a sectional view taken substantially along the line 55 of Fig. 4.

Fig. 6 represents an enlarged sectional view taken substantially alongthe line 5 6 of Fig. 5.

Fig. 7 represents an enlarged sectional view taken substantially alongthe line i-'l of 4.

In the embodiment of the invention selected for illustration, myimproved presser device is shown applied to a sewing machine having abed Ii] and a` head Journaled below the bed l0 is a rotary hook l2 andthe usual feed rock-shafts I3 and ld which impart a four-motion movementto a feed-dog l5 through the medium of a reedbar IS, in the usual andweil known manner- Mounted upon the bed lil is a conventionalthroat-plate Il formed with slots I8 through which the feed-dog l5operates.

Journaled for reciprocatory movement in the head I is a needle-bar I9carrying an eye-pointed needle 2t. Also journaled for a right line upand down movement in the head is the usual spring-depressed presser-bar2|. For a more complete and detailed description or the sewing machinemechanism, reference may be had to the patent of Kaier No. 2,206,285,dated July 2, 1940.

The present invention comprises a presser-foot shank 22 which may bedetachably secured at its upper end portion to the sewing machinepresserbar 2| in a conventional manner by means ofl a screw 23.Pivotally attached to the lower portion of the shank 22 by means of' ahorizontal pin 2li is a primary sole plate `25 having a forward toeportion 26, a rearward heel portion 2l' and a needle-receiving aperture28 disposed between such portions.` Also pivotally carried upon theabove noted horizontal pin 24 is a substantially L-shaped bell-crank;lever or arm 2S whose horizontally disposed limb 30 has pivotallymounted thereon an auxiliary or secondary sole-plate Y3| which isnormally disposed directly in front or the primary Sole-plate 25. A. pin32 pivotally secures the secondary sole-plate 3| to the free end portionof the limb 3U,v The vertically disposed limb 33 ofthe bell-crank leveris apertured as at 34 so as to receive a horizontally disposed post 35rigidly carried upon and extending rearwardly from` the presser-footshank 22. Carried upon and adjustable lengthwise of the post 15,5 is acollar 3d which functions as an abutment for one end of a coil spring3'1 whose other end engages a washer 38 carried by the post 3,5 andabutting against the bell-crank lever for the purpose of biasing theauxiliary sole-plate 3| toward the sewing machine throat-plate I1 andagainst the work which is designated by the numeral 39.,

By adjusting the collar 36 lengthwise of the arm 35, by means of a setscrew 40 carried by the collar 36, the clamping force of the auxiliaryor Vsecondary sole-plate 3l may b-e varied. By referring to Figs. 1 and4 it is to be understood that whenever the presser-bar 2l is raised offthe work, by means of the conventional presser-bar lifting mechanism notdisclosed herein, the upper limb 33 of the pivot arm 29 will engage anabutment member 32 so that the movement of the arm about its pivot pin24 will be arrested. In a preferred form of the present invention, theprimary sole-plate 25 is disposed directly over and in cooperativerelation with the lower feed-dog l while the secondary sole-plate 3l islocated forwardly of the Yfeed-dog.

In utilizing the present device, the effective force of the spring 31 isadjusted by means of theV collar 36 so that the secondary sole-plate 3lwill forcibly engage the elastic work material 39 to the end thatpressure is exerted upon the work between the throat-plate I1 and theauxiliary s ole-plate 3l. Thus, as the feed-dog l 5 functions,incooperation with the primary sole-plate 25, to advance the work 3Spast the stitching area, the elastic work material 39 will be stretchedin an area defined between the secondary and primary sole-plates. Thestitches 4l, therefore, will be formed in the work while the latter isin this stretched condition. However, since the elastic needle thread,designated by the numeral 42, is stretched in a conventional mannerduring the stitch setting operation, it is possible by properlyadjusting the spring 31 to stretch the work 39 in a manner proportionalto the thread stretch, so that the resulting stitched work will have notendency to pucker whenthe thread and the work material resume theirrespective natural states.

' said primary sole-plate, spring means acting upon said arm to bias thelatter about its pivot and 'In this connection reference may be had toFig. 2

which illustrates a longitudinal section through a piece of workmaterial made up of upper and lower plies 43 and 44 which are securedtogether by means of lock-stitches consisting of an upper needle thread42 and a lower bobbin thread 4S which have been concatenated together inthe usual manner. In a conventional type of sewing machine the feed-dogand presser-foot function to feed the work-plies past the stitching areawithout stretchingl the plies an appreciable amount. However, aconventional type sewing machine does stretch an elastic needle-threadduring the setting of the stitches with the result that when thestitching operation is complete and the work is clear of thepresser-foot, the stitches will tend to gather or pucker the work Vasillustrated in Fig. Y2. The present presser-foot,

however, functions in cooperation with the fourmotion feed-dog l5 tostretch the work'plies 43 and 44 during their movement up to thestitching area so that, when the stitches are formed in thework-material, the latter will be stretched to the end that theresulting stitched material relativeto said primary sole-plate, andmeans for varying the pressure of said spring means upon said arm.

2. A sewing machine presser-foot comprising, a shank adapted to have itsupper end attached to the presser-bar of a sewing machine, a postsecured to and extending laterally from an intermediate portion of saidshank, a primary soleplate pivotally carried by the lower end of saidshank and including a toe portion, a heel portion and a needle apertureformed between such portions, a substantially L-shaped arm having thelower limb thereof pivotally carried by the lower end of said shankmember so that such limb will normally extend over the toe portion ofsaid primary sole-plate, the upper limb of said arm being apertured forreceiving therein said post, a coil spring carried by said post andengaging said arm thereby to bias the latter about its pivot, means forselectively varying the pressure of said springagainst said arm, and asecondary Vsoleplate pivotally carried by the end of the lower limb ofsaid arm and being disposed directly in front of the toe portion of saidprimary sole-plate.

3. A sewing machine presser-foot comprising, a shank adapted to have itsupper end attached to the presser-bar of a sewing machine, a postsecured to and extending laterally from an intermediate portion of saidshank, a primary soleplate carried by the lower end of said shank andincluding a toe portion, a heel portion and a needle aperture formed insaid sole-plate between such portions, a substantially L-shaped-armhaving the lower limb thereof pivotally carried by the lower end of saidshank member so that such limb will normally extend over the toe portionof said primary sole-plate, the upper limb of said arm being aperturedforreceiving therein said post, a coil spring carried by said post andengaging said arm in a direction to bias the latter about its pivot, anda secondary sole-plate carried by the end of the lower limb of said armand being disposed directly in front of the toe portion of said primarysole-plate.

RALPH E.Y JOHNSON. CHARLES A. KESSLER.

REFERENCES YCITED The following references are of record in the le ofthis patent: Y

UNITED STATES PATENTS Germany Y Apr. 23, 1894

